This research study is aimed at investigating mechanisms involved in the predisposition to inherited lung diseases. A broad study of Alphal-antitrypsin deficiency is the basic topic under study; currently the mechanism for the block in release of antitrypsin of the Z type from the liver is being investigated. The usefulness of screening for antitrypsin deficiency in junior high school age subjects is also being investigated. Other mechanisms being studied include the role of leukocytic protease content in the pathogenesis of pulmonary emphysema or other lung diseases. A newly discovered relationship between an enzyme in the blood, angiotensin-coverting-enzyme, and sarcoidosis has been discovered, and this relationship is being intensively explored. Finally, various potential abnormalities of enzymes in the blood of patients with cystic fibrosis are being explored in an attempt to derive a useful test for heterozygotes and possibly to disclose the basic enzyme defect of that disease.